The long-range objective of this proposal is further improvement in the treatment of cancer in children through the participation of investigators at the Vanderbilt University School of Medicine in Children's Cancer Study Group (CCSG). The Multidisciplinary team of investigators from Vanderbilt are pooling resources with comparable teams from other institutions to investigate the biology, treatment, and epidemiology of the childhood cancers. Specific aims can be summarized in terms of Vanderbilt's contributions to the Group's scientific endeavors and administrative leadership. These include the following: 1. Through participation in disease-specific Strategy group's priorities and develop new strategies for therapeutic studies of acute lymphocytic leukemia (All), Hodgkin's disease, 2. Through Study Committee Chairmanship, provide leadership the development, conduct, analysis, and reporting of investigation dealing with the treatment of "average risk" and "high risk" ALL and with the biology and treatment of neuroblastoma. 3. Through participation as Study Committee members, assist in the conduct of studies concerned with the treatment of "low risk" ALL in infants, Hodgkin's disease, astrocytoma, and medulloblastoma 4. Provide leadership in the development and interpretation of studies that assess the developmental neuropsychologic sequelae of curative therapy of ALL. 5. Through committee participation contribute to the development and analyses of studies of investigation drugs, and to identify means for improving supportive care. 6. Provide administrative leadership for the Tumor Imaging Committee, the Affiliate Activities Steering Committee, and the Affiliate Activities Program Committee. In addition, investigators will continue to enlist the participation of Vanderbilt patients in CCSg research protocols so as to facilitate the expeditious conduct and timely conclusion of Group studies.